The present invention relates generally to refrigeration systems, and, more specifically, to refrigeration systems that use a Stirling cooler as the mechanism for removing heat from a desired space. More particularly the present invention relates to refrigerated apparatus for vending or dispensing containers, for dispensing cold liquids and for chilling containers and the contents thereof.
Refrigeration systems are prevalent in our everyday life. In the beverage industry, refrigeration systems are found in vending machines, glass door merchandisers (xe2x80x9cGDMsxe2x80x9d) and dispensers. In the past, these units have kept beverages or containers containing a beverage cold using conventional vapor compression (Rankine cycle) refrigeration apparatus. In this cycle, the refrigerant in the vapor phase is compressed in a compressor, causing an increase in temperature. The hot, high pressure refrigerant is then circulated through a heat exchanger, called a condenser, where it is cooled by heat transfer to the surrounding environment. As a result of the heat transfer to the environment, the refrigerant condenses from a gas to a liquid. After leaving the condenser, the refrigerant passes through a throttling device where the pressure and temperature both are reduced. The cold refrigerant leaves the throttling device and enters a second heat exchanger, called an evaporator, located in the refrigerated space. Heat transfer in the evaporator causes the refrigerant to evaporate or change from a saturated mixture of liquid and vapor into a superheated vapor. The vapor leaving the evaporator is then drawn back into the compressor, and the cycle is repeated. A variation of the vapor compression cycle as outlined above is the transcritical carbon dioxide vapor compression cycle where the condenser is replaced with an ultra-high pressure gas cooler and phase change does not occur.
Stirling coolers have been known for decades. Briefly, a Stirling cycle cooler compresses and expands a gas (typically helium) to produce cooling. This gas shuttles back and forth through a regenerator bed to develop much larger temperature differentials than the simple compression and expansion process affords. A Stirling cooler uses a displacer to force the gas back and forth through the regenerator bed and a piston to compress and expand the gas. The regenerator bed is a porous element with a large thermal inertia. During operation, the regenerator bed develops a temperature gradient. One end of the device becomes hot and the other end becomes cold. David Bergeron, Heat Pump Technology Recommendation for a Terrestrial Battery-Free Solar Refrigerator, September 1998. Patents relating to Stirling coolers include U.S. Pat. Nos. 5,678,409; 5,647,217; 5,638,684; 5,596,875; and 4,922,722.
Stirling coolers are desirable because they are nonpolluting, are efficient and have very few moving parts. The use of Stirling coolers has been proposed for conventional refrigerators. See U.S. Pat. No. 5,438,848. However, it has been recognized that the integration of free-piston Stirling coolers into conventional refrigerated cabinets requires different techniques than conventional compressor systems. D. M. Berchowitz et al., Test Results for Stirling Cycle Cooler Domestic Refrigerators, Second International Conference. To date, the use of Stirling coolers in beverage vending machines, GDMs and dispensers is not known.
Therefore, a need exists for adapting Stirling cooler technology to conventional beverage vending machines, GDMs, dispensers and the like.
The present invention satisfies the above-described needs by providing novel applications of Stirling cooler technology to the beverage industry. A novel apparatus in accordance with the present invention comprises an insulated enclosure, the enclosure having an outside and an inside and at least two Stirling coolers disposed outside the enclosure. The Stirling coolers each having a hot portion and a cold portion and the Stirling coolers are spaced from each other. A heat-conducting member is provided for each Stirling cooler. A first portion of each heat-conducting member is connected in heat exchange relationship with the cold portion of each Stirling cooler. The heat-conducting member extending from the Stirling cooler through the insulated enclosure such that a second portion is inside the enclosure. A heat-conducting plate is connected in heat exchange relationship to at least one of the second portions of the heat-conducting member inside the enclosure.
In an alternate embodiment, the present invention comprises an insulated enclosure having a top and a first heat-conducting member having opposite ends. The first member extending through the top of the enclosure such that one end extends into the enclosure and the other end extends outside the enclosure. A first Stirling cooler is disposed outside the enclosure and has a hot portion and a cold portion. The cold portion of the first Stirling cooler is removably connected in heat exchange relationship adjacent the end of the first member extending outside the enclosure A first heat-conducting plate is disposed adjacent the top of the enclosure, the plate being connected in heat exchange relationship adjacent the end of the first member extending inside the enclosure, such that heat from air in the enclosure can flow from the air surrounding the first plate through the plate and the first member to the cold portion of the first Stirling cooler.
The present invention also comprises a method of cooling the inside of an insulated enclosure. The method comprises removably connecting in heat exchange relationship a cold portion of a first Stirling cooler to a first heat-conducting member extending from outside the enclosure to inside the enclosure, the first member being connected in heat exchange relationship to a plate disposed inside the enclosure.
Another embodiment of the present invention comprises an insulated enclosure having an inside, an outside and a top. A first Stirling cooler having a cold portion and a hot portion is disposed so that the cold portion of the first Stirling cooler extending through the enclosure such that the cold portion is disposed inside the enclosure and the hot portion is disposed outside the enclosure. A first plate disposed inside the enclosure and adjacent the top of the enclosure is connected in heat transfer relationship to the cold portion of the first Stirling cooler.
In an alternate embodiment, the present invention comprises a method of cooling the inside of an insulated enclosure having an inside, an outside and a top. The method comprises removably connecting in heat exchange relationship a cold portion of a Stirling cooler to a first heat-conducting plate disposed inside the enclosure and adjacent the top of the enclosure, the hot portion of the Stirling cooler being disposed outside the enclosure.
In still another disclosed embodiment, the present invention comprises a method of cooling the inside of an insulated enclosure having an inside, an outside and a top. The method comprises removably connecting in heat exchange relationship a cold portion of a Stirling cooler and a first heat-conducting plate disposed inside the enclosure adjacent the top of the enclosure. The hot portion of the Stirling cooler is disposed outside the enclosure.
Another embodiment of the present invention comprises a transportable apparatus comprising an insulated enclosure for containing a plurality of containers, the enclosure having an inside, an outside and a door for dispensing containers from the inside to the outside, the enclosure being mountable in a vehicle. A dispensing path is defined by a pair of spaced members, the dispensing path being for receiving a plurality of containers in stacked relationship and for dispensing them sequentially from the apparatus. A portion of the dispensing path adjacent the door is at least partially defined by a plate made of a heat transfer material, such that the containers in the dispensing path contact the plate before being dispensed through the door. A Stirling cooler is disposed outside the enclosure, the Stirling cooler having a hot portion and a cold portion, the Stirling cooler being powerable by the vehicle""s electrical system. A heat-conducting member connects the plate to the cold portion of the Stirling cooler in heat transfer relationship.
In another embodiment, the present invention comprises contacting at least a portion of a container to be dispensed from an insulated enclosure with a heat-conducting plate before the container is dispensed from the enclosure, such that heat is transferred from the container to the plate, the plate being connected in heat transfer relationship to a cold portion of a Stirling cooler.
In still another embodiment, the present invention comprises contacting at least a portion of a container to be dispensed from an insulated enclosure disposed in a vehicle with a heat-conducting plate before the container is dispensed from the enclosure, such that heat is transferred from the container to the plate, the plate being connected in heat transfer relationship to a cold portion of a Stirling cooler, the Stirling cooler being powered by an electrical system from the vehicle.
In another embodiment, the present invention comprises an insulated enclosure having an outside and an inside and means disposed inside the enclosure for defining a path for receiving a plurality of containers in stacked relationship and for dispensing containers therefrom. Heat-conducting means are associated with the path means such that at least a portion of the containers stacked in the path contact the heat-conducting means before the containers are dispensed from the apparatus. A Stirling cooler is disposed outside the enclosure, the Stirling cooler having a hot portion and a cold portion. A means is provided for circulating a heat-conducting fluid from the cold portion of the Stirling cooler to the heat-conducting means and back to the cold portion such that the heat-conducting fluid undergoes heat exchange with the heat-conducting means and with the cold portion of the Stirling cooler.
In a further embodiment, the present invention comprises an insulated enclosure having an outside, an inside and an openable door for accessing containers stored inside the enclosure. At least one vertically oriented heat pipe is disposed inside the enclosure. At least one heat-conducting shelf is disposed inside the enclosure, the shelf being connected in heat exchange relationship to the heat pipe. At least one Stirling cooler having a hot portion and a cold portion is provided outside the enclosure. The cold portion of the Stirling cooler is connected in heat exchange relationship with the heat pipe.
In another embodiment, the present invention comprises a Stirling cooler having a hot portion and a cold portion. A fluid heat exchanger is disposed adjacent the cold portion of the Stirling cooler and in heat exchange relationship therewith. A fluid reservoir is provided for containing a heat transfer fluid, the fluid reservoir being connected to the fluid heat exchanger for fluid communication therewith. A pump is operative to circulate the heat transfer fluid from the fluid reservoir through the fluid heat exchanger and back. An inner flexible annular sleeve is provided for containing the heat transfer fluid and for receiving a container therein in heat exchange relationship therewith, the sleeve being connected to the fluid reservoir for fluid communication therewith. A pump is operative to circulate the heat transfer liquid in the fluid reservoir through the inner sleeve and back. An annular outer inflatable sleeve is disposed about the inner sleeve, such that when the outer sleeve is inflated, the inner sleeve is pressed into contact with a container received therein and when the outer sleeve is not inflated, the container can be removed from the inner sleeve. A pump is operatively associated with the outer sleeve to selectively inflate and deflate the outer sleeve.
In still another embodiment, the present invention comprises a Stirling cooler having a hot portion and a cold portion. A first fluid heat exchanger is disposed adjacent the cold portion of the Stirling cooler and in heat exchange relationship therewith. A fluid reservoir for containing a heat transfer fluid is connected to the first fluid heat exchanger for fluid communication therewith. A pump is operative to circulate the heat transfer fluid from the fluid reservoir through the first fluid heat exchanger and back. A second fluid heat exchanger is provided having a fluid inlet, a fluid outlet, a heat transfer fluid inlet and a heat transfer fluid outlet. The second heat exchanger is operative to transfer heat from a fluid flowing from the inlet to the outlet to a heat transfer fluid flowing from the heat transfer fluid inlet to the heat transfer fluid outlet. The fluid inlet is connectable to a source of fluid under pressure so that fluid can flow from the fluid inlet to the fluid outlet. A pump is operative to circulate the heat transfer fluid from the fluid reservoir to the second fluid heat exchanger and back.
In another embodiment, the present invention comprises circulating a heat transfer fluid from a fluid reservoir to a heat exchanger in heat exchange relationship with a cold portion of a Stirling cooler, such that the heat transfer fluid in the reservoir is at a desired temperature. A container containing a fluid to be chilled is positioned inside a flexible annular sleeve fillable with the heat transfer fluid from the reservoir. The sleeve is pushed into heat transfer contact with the container and the heat transfer fluid from the fluid reservoir is circulated through the sleeve and back, such that heat from the container and the contained fluid is transferred to the heat transfer fluid circulated through the sleeve. The sleeve is released from contact with the container and the container is removed from the sleeve.
In still another embodiment, the present invention comprises circulating a heat transfer fluid from a fluid reservoir to a heat exchanger in heat exchange relationship with a cold portion of a Stirling cooler, such that the heat transfer fluid in the reservoir is at a desired temperature. The heat transfer fluid in the fluid reservoir is circulated through a second heat exchanger and back. A fluid to be chilled is flowed through the second heat exchanger so that heat from the flowing fluid to be chilled is transferred to the heat transfer fluid circulated through the second heat exchanger.
In another embodiment, the present invention comprises an insulated enclosure having an outside and an inside and means disposed inside the enclosure for defining a path for receiving a plurality of containers in stacked relationship and for dispensing individual containers therefrom. A heat-conducting means is associated with the path means such that at least a portion of each container stacked in the path contacts the heat-conducting means before each container is dispensed from the path means. A Stirling cooler is disposed outside the enclosure, the Stirling cooler having a hot portion and a cold portion. At least one heat pipe is connected to the cold portion and to the heat-conducting means.
In a further embodiment, the present invention comprises an insulated enclosure having an outside and an inside and a door for accessing containers contained in the enclosure. At least one heat-conducting shelf is disposed inside the enclosure for supporting a plurality of containers thereon. A Stirling cooler having a hot portion and a cold portion is disposed outside the enclosure, such that the cold portion of the Stirling cooler extends into the enclosure. The cold portion of the Stirling cooler is connected to a heat-conducting shelf upon which containers can be placed. Alternately, the Stirling cooler is disposed outside the enclosure and one end of at least one heat pipe, or other heat-conducting material, is connected to the cold portion and the other end is connected to the heat-conducting shelf.
In yet another disclosed embodiment, the present invention comprises a fluid container containing a heat transfer fluid. The cold portion of the Stirling cooler is connected in heat exchange relationship to a first heat exchange member in contact with the heat transfer fluid in the container. A source of a fluid to be chilled is connected in fluid communication with a second heat exchange member in contact with the heat transfer fluid in the container.
In still another disclosed embodiment, the present invention comprises a Stirling cooler having a hot portion and a cold portion and a first heat exchanger in heat exchange relationship with the cold portion of the Stirling cooler and operative to remove heat from a heat transfer fluid in the first heat exchanger. The invention also comprises a fluid reservoir for containing a phase change fluid and a second heat exchanger disposed in the phase change fluid in the reservoir and in fluid communication with the heat transfer fluid in the first heat exchanger and operative to transfer heat between the phase change fluid and the heat transfer fluid in the second heat exchanger. A third heat exchanger is in fluid communication with the heat transfer fluid in the second heat exchanger and is operative to remove heat from a fluid to be chilled in heat transfer relationship with the third heat exchanger. A pump is operative to circulate the heat transfer fluid from the first heat exchanger to the second heat exchanger to the third heat exchanger and back.
In another disclosed embodiment, the present invention comprises removing heat from a heat transfer fluid in heat exchange relationship with a cold portion of a Stirling cooler and circulating the heat transfer fluid to a first heat exchanger disposed in a phase change fluid in a fluid reservoir and then through a second heat exchanger. The invention further comprises flowing a fluid to be chilled through the second heat exchanger so that heat from the flowing fluid to be chilled is transferred to the heat transfer fluid circulating through the first and second heat exchangers.
Accordingly, it is an object of the present invention to provide improved refrigerated apparatus used in the beverage industry.
Another object of the present invention is to provide an improved vending machine.
A further object of the present invention is to provide an improved GDM.
Still another object of the present invention is to provide an improved beverage dispenser.
Another object of the present invention is to provide an improved system for chilling containers and fluids.
Another object of the present invention is to provide vending machines, GDMs and dispensers that have reduced energy consumption.
Yet another object of the present invention is to provide vending machines, GDMs and dispensers using refrigeration systems that have improved reliability and serviceability.
These and other objects, features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments and the appended drawing and claims.